from typing import Optional


class KeyManager:
    def __init__(self):
        self._keys = {}

    def set_key(self, provider: str, key: str):
        self._keys[provider] = key

    def get_key(self, provider: str) -> Optional[str]:
        return self._keys.get(provider)


_global_key_manager = KeyManager()


def get_key_manager() -> KeyManager:
    """Get the global KeyManager instance."""
    return _global_key_manager